Notably, Tn and Ts housed, MCD diet fed mice, despite differences in NAFLD severity, exhibited similar hepatic expression of insulin signaling (Pparγ and Irs1) and lipid metabolism-associated genes (Lxrα, Lipe, Chrebp, and Srebp) (Supplementary Figures 4J, K). Here, IRS1 is linked to metabolic dysfunction-associated steatotic liver disease.